In connection with so-called jump-lifts, the elevator hoistway is taken into use already before the full length of the elevator hoistway has been completed. The top part of the elevator hoistway is constructed at the same time as an elevator car moving in the already completed bottom part of the elevator hoistway serves on the lower floors of the building. The elevator car moving in the bottom part of the elevator hoistway is supported and moved during the construction-time use suspended on hoisting ropes that are supported by a supporting structure in the elevator hoistway, which ropes are moved with a hoisting machine, which can be supported e.g. on a platform comprised in the aforementioned supporting structure. The installation work in the parts of the elevator hoistway above this supporting platform is done from a movable platform or corresponding. When the part of the elevator hoistway under construction above the supporting platform has reached a sufficient stage of completion, the completed part of the elevator hoistway can be taken into use. In this case a jump-lift is performed, wherein the supporting platform is lifted to a higher position in the elevator hoistway, thus extending the operating area of the elevator car upwards. A worksite crane in use in the construction of the building or a lighter lifting device to be supported on the building and arranged for the site for the purpose of the elevator installation can, for example, be used for the lifting. When the elevator hoistway has reached its final height, the jump-lift is converted into the final elevator of the building. In prior art the supporting platform is supported for the period of time between jump-lifts e.g. on the wall structures of the elevator hoistway while resting on support elements comprised in the frame of the supporting platform, each of which elements can be moved in the lateral direction from the supporting platform into an extended position and back towards the platform into a retracted position, supported on which support elements in their extended position the frame of the supporting platform can be lowered to rest on top of the wall structures of the elevator hoistway, for the vertical support of the supporting platform in the elevator hoistway, and when in the retracted position of which support elements the supporting platform can be displaced in the vertical direction in the elevator hoistway without being obstructed by the support elements. This type of support elements is used inter alfa in the solution presented by publication WO2010100319A1.
The supporting structure is generally such that it comprises a platform suited for working or a plurality of such platforms one above the other. For example, a lower platform can have elevator components, such as the machine and/or diverting pulleys, in the proximity of which it must be possible to work safely while standing on the platform. Likewise, a lower platform can have components, in the proximity of which it must be possible to work safely while standing on the platform. A higher platform can have e.g. hoisting means, such as e.g. a hoist, intended for lifting the supporting structure itself. The support means are conventionally disposed at the level of the lower working platform, through which platform the ropes also pass. The support means are disposed in certain points depending on the reeving, which must pass through the platform. Since reevings are at least to some extent different in different installation sites, it has often been necessary to plan an own type of support element placement for each installation site. A problem has also been that the placement of the support points of the building might have become difficult.
A building is generally formed to comprise a plurality of floor landings, onto which is an access opening from the elevator hoistway. There might be a need to form the floor-to-floor heights of the floor landings of the same building to differ from each other. Likewise, the floor-to-floor heights of different buildings differ from each other. Owing to these differences, the size of a supporting structure comprising work platforms one above the other has caused at the point of some floors a situation in which the work platform is well above the floor landing, which could cause a dangerous situation, particularly in an evacuation situation when an exit from the working platform must be made quickly. Namely, rapid transfer away from the work platform is generally possible only by passing through the opening of the floor landing.